<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div class="wrapper">
      <div class="red cir"></div>
      <div class="green cir"></div>
      <div class="black cir"></div>
      <div class="blue cir"></div>
      <div class="yellow cir"></div>
    </div>
  </body>
  <style>
    .wrapper {
      position: fixed;
      top: 50%;
      left: 50%;
    }
    .cir {
      border-radius: 50%;
      width: 100px;
      height: 100px;
    }
    .red {
      border: 3px solid red;
    }
    .yellow {
      border: 3px solid yellow;
    }
    .blue {
      border: 3px solid blue;
    }
    .black {
      border: 3px solid black;
    }
    .green {
      border: 3px solid green;
    }
  </style>
</html>
